Added constructors that call the loading methods to the Image class.  Updated the only code that constructs the image class to use it.
Code fix for a previous commit.
Created some boilerplate code for a TextureManager.
Created boilerplate for EntresolManager class.
Minor doc fixes and code styling fixes.  Also updated all the appropriate managers to inherit from EntresolManager instead of ManagerBase.
Added some debug output code to test physics simulation steps.
Adjusted many of the "bells and whistles" we had enabled for the engine demo physics simulation to attempt to troubleshoot it's performance problems.